SARS病变组织细胞凋亡检测及其意义

目的 检测SARS病变组织标本中的细胞凋亡情况和凋亡细胞类型，探讨细胞凋亡在SARS发病过程中的作用及可能机制。方法 DNA片段原位末端检测和免疫组化碱性磷酸酶法单染和双染检测正常组织和SARS病变组织中的细胞凋亡以及白细胞分化相关抗原CD3、CD4、CD8、CD45RA、CD20、CD68的表达情况。结果 与正常组织相比，SARS病人的脾脏、肺组织和淋巴结细胞凋亡明显增多，凋亡细胞包括肺泡上皮细胞、淋巴细胞和单核／巨噬细胞等；各病变组织内均有大量CD68^ 单核／巨噬细胞；病变肺组织基本没有CD45RA^ ／CD20^ B细胞和CD4^ /CD8^ T细胞浸润，淋巴结和脾脏的CD4^ ／CD8^ T细胞、CD45RA^ ／CD20^ B细胞也明显减少，现存的具有上述抗原特性的T细胞和B细胞较少凋亡。结论(1)细胞凋亡现象在SARS病变组织中普遍存在，提示细胞凋亡在SARS发病过程中起一定作用；(2)病变组织内浸润的炎细胞主要为单核细胞，说明单核细胞可能在SARS发病中起重要作用；(3)淋巴结和脾脏的细胞凋亡现象和CD4^ /CD8^ T细胞及CD45RA^ ／CD20^ B细胞减少提示SARS病毒可能对免疫细胞有一定的杀伤效应。

Detection of cell apoptosis in the pathological tissues of patients with SARS and its significance]

OBJECTIVE: To explore the role and mechanism of apoptosis in severe acute respiratory syndrome (SARS). METHODS: Klenow-FragELTM DNA Fragmentation Detection Kit and immunohistochemical alkaline phosphatase detection reagent kit were used to detect cell apoptosis and expressions of CD68, CD20, CD4, CD8 and CD45RA in the pathological tissues of SARS patients. RESULTS: Apoptotic cells increased significantly in the spleen, lung and lymph nodes of SARS patients as compared with normal tissues. The apoptotic cells included pneumocytes, lymphocytes and monocytes, and CD68+ monocytes were observed in abundance in the lung, spleen and lymph nodes of SARS patients. In the lung tissue of the patients, few CD20+/CD45RA+ B cells and CD4+/CD8+ T cells were spotted, and CD20+/CD45RA+ B cells along with CD4+/CD8+ T cells were also significantly decreased in the spleen and lymph nodes, where few conserved B and T cells underwent apoptosis. CONCLUSIONS: Apoptosis is a general phenomenon in SARS, and the invasive cells in the pathological tissues are primarily monocytes, suggesting that apoptosis and invasion of monocyte play important roles in the progression of SARS. The cell apoptosis and decreased number of T cell and B cells in the lungs and CD4+/CD8+ T cells and CD20+/CD45RA+ B cells in the spleen and lymph nodes indicate that the SARS virus may exercise immune cell-killing effect to some extent during its pathogenesis.